Periurethral muscle-derived mononuclear cell injection improves urethral sphincter restoration in rats.

AIMS: Investigate the effect of a novel cell-based therapy with skeletal muscle-derived mononuclear cells (SMDMCs) in a rat model of stress urinary incontinence. METHODS: Male Wistar-Kyoto rats' hind limb muscles were enzymatically dissociated, and SMDMCs were isolated without needing expansion. The cell population was characterized. Twenty female rats underwent urethrolysis. One week later, 10 rats received periurethral injection of 106 cells (SMDMC group), and 10 rats received saline injections (Saline group). Ten rats underwent sham surgery (Sham group). Four weeks after injection, animals were euthanized and the urethra was removed. The incorporation of SMDMCs in the female urethra was evaluated with fluorescence in situ hybridization for the detection of Y-chromosomes. Hematoxylin and eosin, Masson's trichrome staining, and immunohistochemistry for actin and myosin were performed. The muscle/connective tissue, actin and myosin ratios were calculated. Morphological evaluation of the urethral diameters and fractional areas of the lumen, mucosa, and muscular layer was performed. RESULTS: SMDMCs population was consistent with the presence of muscle cells, muscle satellite cells, perivascular cells, muscle progenitor cells, and endothelial cells. SMDMCs were incorporated into the urethra. A significant decrease in the muscle/connective tissue ratio was observed in the Saline group compared with the SMDMC and Sham groups. The proportions of actin and myosin were significantly decreased in the Saline group. No differences were observed in the morphometric parameters. CONCLUSIONS: SDMSC were incorporated into the rat urethra and promoted histological recovery of the damaged urethral sphincter, resulting in decreased connective tissue deposition and increased muscle content.

Deepithelialized Connective Tissue Graft and the Remaining Epithelial Content After Harvesting by the Harris Technique: A Histological and Morphometrical Case Series.

INTRODUCTION: The remaining epithelial layer existent in connective tissue graft (CTG) harvested from the hard palate, which underwent de-epithelization outside the oral cavity, can be histologically detected unless it is completely removed. Its presence may cause adverse esthetics results, affecting thus the color and texture of the receptor site, and an increased risk of presence of scar tissues after surgical procedures. The proposal of this study was to evaluate the CTG (histological and morphometrically) collected from the hard palate using the Harris technique, removing the epithelial layer outside the mouth, assessing the remaining presence of epithelial tissue. CASE SERIES: Fourteen patients (14 CTGs) were included in the present case series study, therefore there were two dropouts. A small part of the tip of the graft was harvested and fixed in formalin solution for histological processing, staining, and then to be morphometrically analyzed. The epithelial tissue and CTGs were assessed by three calibrated and double-blinded professionals. All information was compiled, and the statistical analysis was performed. CTGs obtained had a width average of 1224.26 µm. There was no presence of any residual of the epithelium in three samples, whereas only one had the epithelium tissue covering the entire connective layer. Furthermore, seven samples (approximately 50%) had the presence of epithelium. CONCLUSION: Within the limitation of this study, there was incomplete removal of the epithelial layer after harvesting the CTG using the Harris technique (44.32%), most likely due to its histological persistency, suggesting to be inaccurate the clinical removal.